This invention relates to the field of mobile positioning of mobile devices which may include mobile telephones and wireless transmitters for provision of wireless location-based services which may include mobile location-based game services.
Background art in the field of mobile phone positioning is shown by Klukas, R. W., “A Superresolution Based Cellular Positioning System Using GPS Time Synchronization,” UCSE Report Number 20114, Department of Geomatics Engineering, The University of Calgary, December 1997 and by Swedberg, G., “Ericsson's mobile location solution,” Ericsson Review 4, (1999).
Many mobile positioning systems have over the past several years been developed and deployed on a local, regional as well as a global basis. The most notable of these systems is the US Department of Defense's Global Positioning System (GPS) that has been in existence for the past 30 odd years but only commercialized since the late 80's. Although this system was initially designed and built for navigation it has steadily become a very accurate and reliable mobile positioning system for all types of commercial and consumer applications. A case in point, is provided in an article entitled, “Accuracy is addictive”, in the March, 2002 publication of The Economist Technology Quarterly issue, where the author describes GPS accuracy in the following manner: “Today, the public can get GPS position fixes with an accuracy of three to 15 meters, depending on where they are.” Other comments in this article provide further insight into the usefulness of the accuracy of GPS and where it is going: “Already the basis of a $12 billion global industry, GPS is in example of a self-perpetuating innovation: the better it gets, the more uses people find for it.”
The Russians have an equivalent global navigation satellite system called Glonass however it usefulness has become marginalized due to the cost of maintenance of the system; nontheless, it is capable of providing the same types of position accuracies as GPS. Not to be out done, the Europeans also have started to develop their own version of GPS called Galileo; this system is expected to be operational sometime in the later half of this decade.
Other types of mobile positioning systems have been (and are still being) developed and commercialized in support of the US E911 mandate which is expected to become law by 2005. These other types of mobile positioning systems are typically referred to a terrestrial based mobile positioning systems that are either network-based, network-based/handset-assisted, handset-based or handset-based/network-assisted. These systems employ one of or a combination of the following mobile positioning methods: Signal level, Angle of Arrival (AOA), Time of Arrival (TOA), Time Difference (TDOA/E-OTD/U-TDOA), GPS or Assisted GPS.
Regardless of the type of mobile positioning system and underlying technology characteristics they are all designed with a common goal in mind: to be the most accurate, reliable and low-cost mobile positioning system, full stop. It is clear that these systems will provide varying levels of accuracy and reliability along the way to reaching this common objective. GPS is clearly the front-runner in this regard and as such has gained tremendous momentum as being the globally accepted solution for mobile positioning applications currently and in the future. This is not to say that the other variants won't play a part in the mobile positioning industry but it is quite clear that these other systems will be considered as niche plays.
Having said this, the trend is clear that current and future mobile positioning systems will have to deliver a sufficient level of accuracy and reliability in order to be recognized as at least providing the same level of performance as GPS in order to compete. Therefore it is also clear that any successful mobile positioning system will need to deliver very accurate and reliable positioning performance. And as is being proven with GPS the more accurate and reliable a mobile positioning system is the more uses people find for it.
Case in point, these uses are starting to emerge in many areas and may include information and entertainment based services such as those described in a research report produced by Telematica Instituut, entitled, “Overview of Mobile Information and Entertainment Services”. In this report three mobile location-based services are highlighted in the case studies which include a mobile location-based game service called, Botfighters; a mobile location-based directory service, called Info Here&Now and a locate a friend service, called FindFriends.
It is interesting to note that each of these services is being offered in its current state with a mobile positioning technique called Cell of Origin/Cell-ID (CID) which provides location information based on which cell site and sector the mobile device registered to. This position information is only accurate to within a few hundred meters but is sufficient as a starting point for service providers to offer the said services. It is still too early to determine how much of a limiting effect this level of positioning capability will have on the success of the service being offered. Having said this and reflecting on the trends for mobile positioning systems it is very reasonable to expect that these services will adopt a mobile positioning system which provides increased accuracy and reliability to the users of the service.
These current methods of mobile positioning provide “bookends” to the mobile location-based service spectrum. On the one end you have a course level of accuracy, the cell-site and sector methodology, and on the other end of the spectrum you have a very precise level of accuracy, the GPS system. It can be stated that all mobile positioning systems fall somewhere within these bookends with the majority tending towards the GPS level of accuracy and reliability. Thus the case is made that all mobile positioning systems, except for the cell-site and sector system will eventually be capable of delivering (or nearly so) the GPS level of performance.
The accurate and reliable performance targets are understandable considering the success of GPS, but they bring with them perhaps some unwanted affects that are not perhaps being considered at this moment. Consider the case of the wireless location-based game service called, Botfighters. This service [which currently uses the cell-site and sector approach for its positioning approach and is yielding accuracies to within several hundred meters] has received high acclaim from industry analysts, and users alike. However there are others who have provided insight into the future offering when more accurate position information is offered as part of the game play. These insights are reflected in the following comments on a on-line forum called, INTERESTING-PEOPLE (www.interesting-people.org) where one game reviewer stated, “Here's an alternative vision: you are in a crowded high street, pursuing your quarry using your phone. The handset beeps again and then, just as you close in, a hand clasps your shoulder, spins you around, you get punched in the face, then your assailant grabs your phone and legs it.”
While the person making the comments may perhaps have a pessimistic view of what most other reviewers are calling an exciting and innovative game, he does highlight a very important point that anyone wanting to offer this type of service must consider: the safety and well-being of the game players given the potential for unwanted approaches or worse, physical attacks, from one player onto another knowing that their respective locations are known to sufficient accuracy and reliability that such an event could perhaps transpire quite easily.
It should be noted that in this same on-line forum a response is given by the CEO of the company which produced and currently offers the Botfighter service. In his remarks, the CEO of the company commented about the concerns expressed by reviewer and said, “When accuracy is improved by using GPS receivers in the handsets, the game design will be adopted by introducing sufficient level of inaccuracy in order to protect personal integrity”. He goes on to say, “As a serious game provider we would of course never let the scenario of Mr. Hawkins actually happen in reality”.
This exchange provides valuable insight into how wireless location-based games will have to evolve to guard against such pessimistic but unfortunately all too probable view as described in the on-line forum. This exchange also provides validity to the notion addressed herein that GPS will most likely be the logical choice in upgrading to a higher accuracy mobile positioning system and that the processes that this invention seeks to achieve will have to be deployed to address safety concerns of those involved in services such as wireless location-based games. Furthermore, this exchange provides insight into the fact that current game designs do not incorporate the processes that this invention seeks to achieve.
A crucial question is how does one deal with the disparate demands for differing levels of accuracy for differing service offerings? On the one hand you have those that demand high accuracy and reliability (for E911 services) and on the other hand you have those that do not want to be located to such precision as in the case of the wireless location-based game scenario.
It would be uneconomical (and thus unreasonable) for service providers to operate two mobile positioning systems (i.e. the cell-site and sector approach for services like wireless location-based games and the more accurate network-based or GPS approach for E911 services for example) for any extended length of time and therefore it is to be expected that service providers will adopt the more accurate and reliable mobile positioning systems sooner rather than later.
Case in point, the Unites States situation necessitates an adoption of the higher accuracy mobile positioning systems because of the E911 mandate dictates to have accurate mobile positioning systems in place by 2005. The rest of the world can afford to adopt the lower accuracy approach (i.e. The cell-site and sector method) as there is no such E911 mandate in place for the moment at least. The case as presented demonstrates that the focus for the US at least will be on higher accuracy mobile positioning systems to be put in place in the next several months and hence the rational for focused development on higher accuracy systems. It is further expected that this trend will take hold in other countries as well and thus the lower accuracy approach will be phased out sooner rather than later.
It is quite reasonable to expect that all those involved in developing, building and enhancing their respective mobile positioning systems (except for cell-site and sector approach—this approach is already built into the service providers existing infrastructure) are doing so in a very focused manner by constantly redesigning, developing, building and testing in an continual effort to achieve the highest level of mobile positioning performance attainable all within reasonable cost structures and time limits. In parallel to these efforts the service providers are looking for new and innovative services to leverage their commitment to roll-out higher accuracy mobile positioning systems. New innovative services like mobile location-based games are one such service that service providers in the US are looking to introduce in the US marketplace. The US is also dominated by “anti-big brother” perception where being tracked and located with any degree of certainty is not well received.
These market conditions provide a favorable climate for offering the public this invention that seeks to address fundamental issues regarding the safeguarding of one's well-being during times of leisure and game play and at the same time providing mechanisms to access accurate location information during times when it is needed.